Calculator

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Calculator",
  "description": "Simple Calc With Keyboard Support",
  "version": "0.2",
  "sandbox": {
    "pages": [
      "calculator.html"
    ]
  },
  "app": {
    "background": {
      "scripts": [
        "background.js"
      ]
    }
  },
  "icons": {
    "16": "img-16.png",
    "128": "img-128.png"
  }
}